1. Technical Field
The present invention relates to projectors and cooling control methods.
2. Related Art
In a projector, it is necessary to perform appropriate cooling control depending on an environment in which the projector is used while suppressing noise produced by a cooling fan. For example, in JP-A-2006-145824, a method for driving an air-cooling fan by connecting a temperature detection circuit provided outside a main power supply section in a primary device and a fan drive circuit in a secondary device with a dedicated path provided between the temperature detection circuit and the fan drive circuit in a projector is proposed. Moreover, in JP-A-2008-242018, a method for controlling the rotational speed of a cooling fan by detecting the temperature inside a primary device by transmitting and receiving infrared radiation with a dedicated communication path by using an infrared emitting section provided in the primary device and an infrared receiving section provided in a secondary device is proposed. As described above, the reason why a new path, not an existing path, is provided is that a power-supply unit in the primary device and a power supply route that is insulated from the secondary device are used, which makes it difficult to transmit temperature information to the secondary device by using the power supply route.
However, in these methods, it is necessary to provide a new path and the like for connecting the primary device and the secondary device. This complicates the configuration and increases production costs. Moreover, since the inside of the housing of the projector is used as a path of wind produced by an air intake fan and an exhaust fan, when a new wired path or a new member is added, part of the path of wind is blocked, which may reduce cooling efficiency. Thus, it is preferable that addition of new members be kept to a minimum. Furthermore, since various noise sources are present in the projector, there is a possibility that the temperature data is not transmitted accurately over a wireless path using infrared radiation or the like due to noise.